The Effect of Arterial and Venous Blood Oxygen Pressure on the Blood Glucase Value / 대한마취과학회지

BACKGROUND: The portable glucose meter is useful in operating rooms and intensive care units (ICUs), where blood glucose concentration must be analyzed frequently and rapidly, and provides immediate information for clinical decisions. At present, the glucose-oxidase(GOD) method is used extensively among many glucose measurement methods but blood oxygen concentration affects this blood glucose value because oxygen, at increased concentration, consumes blood glucose which cannot then be measured by GOD method. The purpose of this study is to investigate the effect of blood oxygen pressure on the blood glucose value by GOD method by the comparison of arterial and venous blood glucose values. METHOD: Patients are randomly assigned to FiO2. 0.33(group1; n=15), FiO2 0.5(group2; n=15) and FiO2 1.0(group3; n=15) groups. 20 minutes after intubation, the samples were obtained from artery and vein. Blood glucose concentrations were measured by portable glucose meter, respectively. RESULT: The value of arterial blood glucose when measured by the GOD method could be underestimated more than the value of venous blood glucose by 3~5 mg/dl. CONCLUSION: The blood glucose value obtained by GOD method is certainly affected by increased blood oxygen pressure. The underestimation is not a clinical problem when blood glucose is high, but anesthesiologist should pay attention to hypoglycemia by the GOD method when blood oxygen pressure is high.

Structural and physiological differences between montane and lowland avian eggs and embryos.

A few avian species breed at altitudes up to 6500 m. Embryos in eggs laid at high altitudes are confronted with the problem that gases diffuse more rapidly at low barometric pressure than at sea level. Data on birds breeding up to 4500 m indicate that modifications in eggshell structure and embryonic physiology foster successful development in these groups. At moderate altitudes (up to 3600 m), shell conductance to gases (corrected to 760 torr) is decreased in approximate proportion to the reduction in barometric pressure, thus offsetting the increased tendency of gases to diffuse. At altitudes above 4000 m, the conductance is increased above levels at moderate altitudes, thus fostering improvement in oxygen availability, while increasing rates of water and CO2 losses. Above 4000 m, embryonic physiological properties become increasingly important for coping with hypoxic, hypocapnic, and dehydrated conditions inside the shell. Nothing is known about characteristics of eggshells and embryos in eggs laid between 4500 and 6500 m. Despite years of artificial selection, domestic fowl do not breed successfully much above 3000 m. Embryos of domestic fowl appear highly sensitive to the effects of hypoxia.